Repsol installs its second 100-MW electrolyzer at Petronor

Repsol continues to advance its industrial decarbonization agenda through renewable hydrogen with plans to install its second large-scale electrolyzer at the Petronor refinery in Muskiz, near Bilbao in northern Spain. This follows the company’s approval in September of its first major electrolyzer project in Cartagena, which will have a capacity of 100 megawatts (MW).

The new 100 MW electrolyzer at Petronor represents an investment of €292 million and is scheduled to enter operation in 2029. Classified by the European Commission as an Important Project of Common European Interest (IPCEI), the project is backed by the Spanish government and will receive €160 million in funding from the NextGenerationEU program under Spain’s Recovery, Transformation, and Resilience Plan.

Once operational, the facility will be capable of producing up to 15,000 tons of renewable hydrogen annually, primarily for use in Petronor’s refining processes. As part of the Basque Hydrogen Corridor, it will also supply clean hydrogen to regional industries, supporting decarbonization efforts and helping to avoid up to 167,000 tons of CO₂ emissions each year—comparable to the emissions reduction achieved by two-thirds of Spain’s fully electric vehicle fleet in 2024.

Due to its scale, the project poses a significant technological challenge and is expected to create around 900 direct, indirect, and induced jobs across its development stages. It also builds on Petronor’s existing progress in renewable hydrogen. In 2023, a 2.5 MW electrolyzer became operational, producing around 350 tons of renewable hydrogen annually to supply the refinery and Petronor’s office facilities at the Abanto Zierbena Technology Park near Bilbao.

Additionally, construction began in 2024 at the Port of Bilbao on a 10 MW electrolyzer that will support a synthetic fuels demonstration plant being developed by Repsol in partnership with Aramco, which is expected to begin operations in 2026.

Second large electrolyzer

Repsol is at the forefront of hydrogen production and use in the Iberian Peninsula, accounting for around 60% of Spain’s total output and contributing approximately 4% of overall hydrogen consumption in Europe. In September 2025, the company approved its first large-scale electrolyzer project, a 100 MW facility to be installed at its Cartagena industrial complex.

This renewable hydrogen initiative will be complemented by another major electrolyzer in Tarragona with a planned capacity of 150 MW. Similar to the projects at Cartagena and Petronor, the Tarragona facility will primarily supply Repsol’s own industrial operations. In addition, it is expected to deliver renewable hydrogen to the future Ecoplanta—designed to produce renewable methanol from municipal waste—as well as to other industries in the surrounding area.